Web severing apparatus



Oct. 11, 1966 D. F. DREHER WEB SEVERING APPARATUS 2 Sheets-$heet 1 FiledAug. 27, 1963 D WF 5 A N O D 1966 D. F. DREHER WEB SEVERING APPARATUS 2Sheets-Sheet 2 Filed Aug. 27, 1963 INVENTOR. DONALD FT DRELHER.

United States Patent 3,277,761 WEB SEVERING APPARATUS Donald F. Dreher,P.O. Box 56, East Brookfield, Mass. Filed Aug. 27, 1963, Ser. No.304,920 3 Claims. (Cl. 83-614) This invention relates to means forsevering a continuous web of paper, film or the like, which may betraveling at a relatively high speed. More particularly its primaryapplication is as an essential component in high speed paster or websplicing apparatus in which the leading end of a new roll of paper orthe like is attached to a running or expiring web in order to achieveweb continuity and to permit uninterrupted operation. Its specificfunction in connection therewith is to sever the expiring web, ideallybeing timed so as to minimize the length of the web which trails behindthe splice.

This function usually is accomplished by a jagged-edged guillotine whichis designed to jab into the expiring web, thus causing rupture and webbreak. Such guillotines tend to be massive and complicated in structure,awkwardly space-consuming and often difficult to incorporate into deignwithout compromise. As a consequence of mass and the speed at which theymust function, the amount of energy required for activation is sizablewhich further compounds the massiveness of the supporting structure. Asrunning web speeds increase, the lag inherent in such mechanismsintroduces additional timing problems with respect to lead time oftriggering, especially if the free trailing segment is to be keptminimal in length at diiferent running speeds. Additionally in some veryhigh speed paster installations, abrupt insertion of the guillotine mayupset web tension and result in failure of the paster to bond the twowebs securely together.

In order more facilely to accomplish the severing of such a travelingweb in a direct and simple manner I position a dart-like assembly at oneend of a slotted tubular web-spanning enclosure, the dart-like assemblycarrying a web-severing blade which protrudes through the lengthwiseslot of the tubing. The slotted tube is positioned in web-deflectingcontact with the expiring web. At the desired instant the blade-carryingdart is fired to the opposite end of the tubing Where it is cushioned toa stop and retained, having slit the web cleanly from edge to edge inits bullet-like traverse. This web serving method may aptly bedesignated, The Flying Blade.

Thus the basic object of the instant invention is to pro vide simple andfoolproof means for cleanly severing a traveling web.

Another object is to reduce the space occupied by the web severingdevice.

Still another object is to simplify overall design, permitting optimalplacement with minimal mechanical conflict and functional compromise.

A further object is to minimize the time-lag factor and to approachinstantaneousness in web cut-off, permitting greater precision andcloser timing.

A still further object is to eliminate tension upset 0ccasioned byoperation of the web severing device.

Still another object is to minimize the necessity for high tension inaccomplishing web severance.

These and other objects of the subject invention may best be understoodby referring to the accompanying drawings in which FIGURE 1 is aperspective view showing a running web of paper in defiective contactwith, and being severed by, the device described herein.

FIGURE 2 is a perspective view of one end of the slotted tube or barrel,partially cut away, exposing the dart assembly and spring drive.

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FIGURE 3 is .a sectional view of the central or body portion of theblade-carrying dart assembly.

FIGURE 4 is a part section view of the powered end of the tubularhousing showing a pneumatic cylinder with its piston bearing against thecentral shaft of the dart assembly.

FIGURE 5 is a similar view showing an explosive I cartridge in thrustingposition against the trailing end of the darts central shaft.

FIGURE 6 is a similar view showing a high pressure air tank insertedinto the trailing end of the darts central shaft in such manner as toprovide rapid initial acceleration and continuing jet thrust behind themotionable assembly as it traverses the full width of the traveling web.

Referring to FIGURE 1, the upwardly traveling web 1 is deflectively incontact with the tubularweb-spanning element 2 which may be eitherrigidly or cushionably supported in whatever manner best suits itsfunction in any particular application. In transverse motion through theweb-spanning barrel 2 and protruding from the lengthwise slot, 3 is. thesevering blade 4, shown slitting the traveling web 1 whose leading freeend 5 is starting to fall away as it is severed.

FIGURE 2 shows one end of the web-spanning barrel 2 which is partiallycut away showing the dart assembly 6 at rest inside the tubularenclosure 2. The dart assembly 6 comprises a central shaft 7, axiallypositioned within the barrel-like enclosure 2 by a webbed body 8 towhich is affixed the severing blade 4. The tube-contacting faces 9 ofthe darts webbed body 8 are adequately clearanced so as to permit freeflight through the barrel enclosure 2 and suitably dimensioned for axialstability and bearing surface area. Ideally the dart assembly 6 shouldbe aerodynamically contoured and its webbed body 8 sparinglycross-sectioned so as to minimize air resistance to its ,bullet-likeflight.

FIGURE 3 details one form of the dart assembly. Its body section 8comprises three degree segments between two of which the severing blade4 is inserted. These several pieces are fastened together with machinescrews 19, clamping the body section 8 solidly against thematchacme-type groove 13 recessed 14 at spaced intervals to simplifystep-loading and hold the plunger 11 at any given setting under load.The inboard end of the compression spring 10 through its dimpled thrustdisc 21, bears against the trailing end of the dart assemblys centralshaft 7 which is axially bearinged in a supporting guide 15 andreleasably held by a pivoted pawl 16 latched into the rec'ess 17 in thecentral shaft 7. For convenience in fabrication and maintenance, thethrust motor assembly may be enclosed within a cylindrical sleeve 22 inthe manner .illustrated.

Pneumatic propulsion may be achieved by means of pressurized aircylinder or bellows with quick release mechanism, or by ultra highpressure air meterably injected, utilizing techniques developed for usein air pistols and dart guns. FIGURE 4 illustrates a pneumatic thrustingarrangement in which figure, as in all the drawings, equivalent partsare similarly referenced, showing a rolling gland type of air motorincluding a cylinder 22, rolling gland 23 and piston 21a bearing againstthe trailing end .and an inverse function of its velocity.

of the darts central shaft 7 which rests coaxially in the supporting.guide 15a. This guide is webbed 24 or vented so that the piston 21a maytravel forward as indicated to its phantomed position unrestricted byair cushioning. The several laterally motionable parts 7, 21a, 23 areheld releasably in their respective positions by the latching mechanism16, 17 which functions identically as hereinbefore described. Thismechanism permits preloading the air motor with pressurized air 25 andthe storage therein of potential energy identical in effect to cookingor preloading the compression spring 1-0. In both examples it will beapparent that preloading the motor element permits instantaneousapplication of peak thrust against the dart assembly at its point ofrepose, or that from which its mass must be accelerated withinmilliseconds into a kinetically energized projectile capable ofaccomplishing its specified purpose. In order that the initial thrust bemaximized, it isadvantageous that the forward motion of the piston 21abe as unrestricted as possible, including the minimizing of its mass,wall friction and frontal air resistance. With respect to mass andfriction, the order of preference among the several common types of airmotors likely would be: metallic of Syl-phon bellows, rolling gland(FIG. 4), standard air cylinder with sealed piston.

Although precluded from many applications due to potential fire hazard,explosive means for controlled-thrust propulsion would appear to bepractical, one of the simpler forms being illustrated in FIGURE in whicha loaded cartridge 26 is chambered 22a, 11b at the outboard end of theweb-spanning barrel 2 and positioned so as to deliver its explosivethrust to the central shaft 7a of the dart assembly when triggered bythe firing pin 27.

In the preferred form of the instant invention, thrust is applied to thecentral shaft 7 in which is concentrated the mass necessary to carry thedart assembly 6, once kinetically energized, reliably to the oppositeend of the slotted barrel 2. The necessary mass thus becomes a directfunction of the amount of work to be performed in its crossweb transitincluding frictional losses and web severance, In practical applicationsinvolving films and lightweight papers, espe cially at higher webspeeds, the velocity of the dart assembly is the primary consideration.When applied to heavier-weight paper and board stocks both the mass ofthe dart assembly and the propulsion force must be increased.

Jet propulsion may also be used, with the power source carried withinthe dart assembly itself, e.g., by insertion of a high pressurecartridge. In such a jet-propelled system the mass of the flying dartassembly may be minimized since propulsion force continues throughoutits crossweb flight, thus facilitating initial acceleration and highvelocity transit. Acceleration may be aided further by cylindricalconfinement of the initial gaseous expansion with the developingpressure exerting direct piston thrust which may be maximized bymomentarily delaying release of the dart assembly.

The last described combination is illustrated in FIG- URE 6 in which ahigh pressure cartridge 28 has been inserted into the hollow trailingend 29 of the darts central shaft 7b, the assembly occupying a chamber22b which may be glanded 30 near its inboard terminus. Inside the neckof the cartridge 28 is provided a membrane 31 which is pierced andorificed by the plunger 32 mounted in the end cap 11b. The plunger 32may be designed to bleed a metered flow of air into the thrust pocket 25when jabbed through the membrane 31, or itmay seal the pierced orificein its forward stroke and permit escape of pressurized gas only whenWithdrawn. Once activated, the developing pressurization within thepocket 25 exerts positive thrust against the piston-like assembly 7b, 28which may be restrained momentarily if desired by delayed release of thedart assembly, the use of the latching mechanism 15, 16, 17 beingoptional and its design subject to modification, including automaticrelease as a function. of thrust exerted against it.

It will be apparent that this type of arrangement provides numerousalternatives by which each of the several factors affecting thrust maybe adjusted so as to maximize performance with the least expenditure ofenergy. In practical terms, since the cost of compressed air per se isof little consequence, the net gain is to increase the range of utilityof such an apparatus with respect to severing Wider and more resistantwebs, either or both being run at higher speed, and to perform withgreater reliability.

Transit of the flying assembly should terminate cushionably, which maybe accomplished by any one of several techniques known to andestablished in the art. The assembly may he held in the opposite end ofthe tubular enclosure or permitted to rebound back to its starting pointand there retained.

Since a flying blade of the character herein described is a highlyefficient severing instrument, and tragically so if ones hand weregrasping the tubular enclosure when the blade was energized, it isadvisable that the protruding edge of the blade be minimally exposed.Nor is greater protruding height advantageous in performing itsfunction, assuming that the Web is in physical contact with the severingdevice. The blade need not necessarily be sharp-edged except in certaincritical applications, since its high velocity renders significant anotherwise insignificant mass such as that of a web of paper. Althoughunder such light duty conditions the actual shaping of the severingblade 4 may not be critical, the profile 18 indicated in FIGURE 2theoretically maximizes shear by its abruptness at its point of contactwith the web, whereas a shallowly inclined slicing profile could negatethe opposing shear force of the paper mass by inverting the blades sinaladvantage, thus demanding that web tension provide the necessaryopposing force. Additionally when considering the effect of web flow athigher operating speeds and especially when thicker webs are being run,a gradually inclined profile would tend to scuff unless it were pitchedslightly so that its deeper cutting sections followed precisely thecutting track. It should also be noted in connection with higher webspeeds that the physical length of blade insertion and the consequenttime interval during which it will tend to obstruct web flow givesfurther support to the abrupt profile, since its shortening reducesfriction between the blade 4 and the slot 3 which develops as a functionof traveling web force.

Although the slotted tubular form of the basic webspanning element ispreferred, the teachings herein con-- tained are applicable to otherforms of crossweb carriage for guidance and support of the flying bladeassembly. It is conceivable that in certain applications ahigh-velocitied missile could be aimed precisely and fired transverselyimmediately adjacent the webs surface, performing its intended functionby means of one or more severing fins without need for structuralguidance in its crossweb transit. In fact, a bullet aimed dead center inthe plane of web travel would surely accomplish web severance withminimal structural involvement. Although indisputably eifective, thehazards inherent in on-guided and/or unshielded high velocity missilespreclude their being given serious consideration for most industrialapplications. A cable-towed and mechanically supported slashing bladealso may be used, driven either by high-speed winch or by parallelpneumatic cylinder oppositely directed, the latter permitting use of acomplete bi-directional cable loop. This form of the device could beadvantageous particularly in handling heavier paperboard since it ispositively-powered throughout its crosswe'b'transit withoutreliance'upon kinetic energy or jet thrust.

To those skilled in the art it will be apparent that the methods hereinoutlined need not be restricted to tail cutting of an expiring web inconnection with automatic paster or web splicing apparatus, nornecessarily to web severance exclusively, howbeit originally sopurposed.

Having thus described my invention, what I claim and desire to secure byLetters Patent of the United States is:

1. In an apparatus of the character described for severing a continuousweb while it is traveling at high speed, in combination with atransversely-motionable severing blade assembly and support means forits guidance crossweb,

a thrust motor forming a part of said apparatus, said motor having -amotionable portion engaging said blade assembly, and

means to hold said assembly motionless in a starting,

rest position while the motor is energized, and thereafter to releasesaid assembly, allowing it to be thrust lengthwise of said support, saidassembly being so contoured relative to said support means as to beminimally opposed by frontal air impaction in its crossweb traverse.

2. A device for severing a continuous web of paper traveling at highspeed, comprising (a) a transversely-motionable severing blade assembly,

(b) a support element providing guidance for crossweb transport of saidassembly adjacent said web,

(0) means for storing latent, explosively activatable energy within saiddevice, and

(d) means for explosively activating said energy into thrust suflicientto propel said assembly into highvelocities traverse of said Web.

3. A device for severing a continuous web of paper traveling at highspeed, comprising (a) a transversely-motionable severing bladeassemcient to propel said assembly into high-velocitied jetpoweredtraverse of said web.

References Cited by the Examiner UNITED STATES PATENTS Engberg 83614 XTacka-berry 83614 Surfus 83614 X Perry 83614 X Jefirey 83-614 X Subklew.

WILLIAM S. LAWSON, Primary Examiner.

WILLIAM W. DYER, ]R., Examiner.

1. IN AN APPARATUS OF THE CHARACTER DESCRIBED FOR SEVERING A CONTINUOUSWEB WHILE IT IS TRAVELING AT HIGH SPEED, IN COMBINATION WITH ATRANSVERSELY-MOTIONABLE SEVERING BLADE ASSEMBLY AND SUPPORT MEANS FORITS GUIDANCE CROSSWEB, A THRUST MOTOR FORMING A PART OF SAID APPARATUS,SAID MOTOR HAVING A MOTIONABLE PORTION ENGAGING SAID BLADE ASSEMBLY, ANDMEANS TO HOLD SAID ASSEMBLY MOTIONLESS IN A STATING, REST POSITION WHILETHE MOTOR IS ENERGIZED, AND THEREAFTER TO RELEASE SAID ASSEMBLY,ALLOWING IT TO BE